Soeew driver



(No Model.)

H. H. TRUE.

SCREW DRIVER.

No. 480,901. Patented June 24, 1890.

UNITED STATES PATENT OFFICE.

IIAROD I-I. TRUE, OF SIOUX CITY, IOl/VA, ASSIGNOR OF ONE-HALF TO DAVID S. SHELLABARGER, OF SAME PLACE.

SCREW-DRIVER.

SPECIFICATION forming part of Letters Patent No. 430,901, dated June 24, 1890.

Application filed February 3, 1890. Serial No. 338.968 (No model.)

To all whom it may concern:

Be it known that I, HAROD H. TRUE, a citizen of the United States, and a resident of Sioux City, in the county of Woodbury and State of Iowa, have invented certain new and useful Improvements in Screw-DriversgandI do hereby declare that the following is afull, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to certain improvements in screw-drivers in which the shank or blade which engages with the screw is automatically revolved to insert the same by simply pressing the handle by whichit is carried.

The invention consists in the novel construction and new combinations of parts hereinafter fully described, and definitely pointed out in the appended claims.

In the accompanying drawings, Figure 1 represents a side elevation of my improved screw-driver combined-with a hammer. Fig. 2 is a central sectional view of the same.

In the said drawings, the reference-mun eral 1 designates a hammer-head, and 2 the handle thereof. The free end of the handle is provided with acentral longitudinal recess 3. This recessis enlarged at its outer end to receive the socket 4C. This socket consists of a cylindrical body 5, secured to the handle in any convenient manner. This socket is provided with a central aperture having spiral grooves 9 therein, as hereinafter described. The forward portion of the body is provided with a central recess 10, which is large enough to receive the head of an ordinary screw.

The numeral 11 designates the shank by which the screw is turned. It consists of a metallic bar twisted to form a number of spirals which correspond and engage with the spiral grooves in the body 5 of the socket. The pitch of the spirals in the socket and shank must be such that the shank can be revolved, and consequently forced into the recess 3, by pressure applied to the end thereof. The forward or outer end of the shank is wedge-shaped, as usual, as seen at 12, to engage with the nick in the head of the screw, and the other end is provided with a loose revolving collar 13, which rotates freely thereon and prevents binding of the shank in the slot.

let desi nates a set-screw secured in the socket and adapted to bind upon the shank and prevent it'from revolving when desired, and also to hold the shank within the recess when not in use.

The operation is as follows: The shank,when it is desired to force or insert a screwinto some article or material, is extended outward to the proper extent. The wedge-shaped end or blade is then inserted in the nick in the head of the screw and pressure applied to the handle. This will cause the shank to be revolved and forced backward in the socket, at the same time revolving or turning the screw and forcing it into the article. When it is desired to withdrawa screw, the setscrew 14: is turned so as to bind against the shank and prevent it from revolving, when the screw can be unscrewed in the ordinary manner.

It will be noted that by forming the spirals by twisting an angular bar they are less liable to be injured, owing to their peculiar shape, in working in the socket than they would be if out in the manner of ordinary screw-threads. The revolving collar on the inner end also prevents binding of the shank in the socket, thus insuring a uniform movement thereof.

Having thus described my invention,what I claim is- The combination, with a handle having a recess 3, with an enlarged recess at its outer end, the socket 4, having central spiral grooves 9 and recess 10, of the shank 11, twisted to form a number of spirals corresponding with the grooves 9, and having at one end a blade to engage with the nick of a screw and at its other end a collar 13, revolving thereon, substantially as described.

In testimony that I claim the foregoing as my own I have hereunto affixed my signature in presence of two witnesses.

IIAROD H. TRUE. \Vitnesses:

E. H. LEwIs, R. E. OANNIEE. 

